diff options
| author | Wolfgang Zarre <lkdev@essax.com> | 2012-01-15 16:21:34 +0400 |
|---|---|---|
| committer | Marc Kleine-Budde <mkl@pengutronix.de> | 2012-02-03 03:25:06 +0400 |
| commit | 2d5091e08c684912ed6b9ca03d1f7b01501b7bf6 (patch) | |
| tree | 62ae0aca80b9fd4d219e5ab4c7ba5ea37dc6613c /drivers/net/can/cc770/cc770_isa.c | |
| parent | 7bb4db93ae59e0faf810a83a8578f56bc968ab01 (diff) | |
| download | linux-2d5091e08c684912ed6b9ca03d1f7b01501b7bf6.tar.xz | |
can: cc770: Fix indirect access deadlock on ISA cards
This fix avoids a deadlock if an interrupt occurs
during consecutive port operations on ISA cards
utilising indirect access via address and data
port.
Tested on a B&R ISA card.
Cc: linux-can@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Wolfgang Zarre <lkdev@essax.com>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'drivers/net/can/cc770/cc770_isa.c')
| -rw-r--r-- | drivers/net/can/cc770/cc770_isa.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/drivers/net/can/cc770/cc770_isa.c b/drivers/net/can/cc770/cc770_isa.c index 4be5fe2c40a5..9f3a25ccd665 100644 --- a/drivers/net/can/cc770/cc770_isa.c +++ b/drivers/net/can/cc770/cc770_isa.c @@ -110,6 +110,11 @@ MODULE_PARM_DESC(bcr, "Bus configuration register (default=0x40 [CBY])"); #define CC770_IOSIZE 0x20 #define CC770_IOSIZE_INDIRECT 0x02 +/* Spinlock for cc770_isa_port_write_reg_indirect + * and cc770_isa_port_read_reg_indirect + */ +static DEFINE_SPINLOCK(cc770_isa_port_lock); + static struct platform_device *cc770_isa_devs[MAXDEV]; static u8 cc770_isa_mem_read_reg(const struct cc770_priv *priv, int reg) @@ -138,18 +143,27 @@ static u8 cc770_isa_port_read_reg_indirect(const struct cc770_priv *priv, int reg) { unsigned long base = (unsigned long)priv->reg_base; + unsigned long flags; + u8 val; + spin_lock_irqsave(&cc770_isa_port_lock, flags); outb(reg, base); - return inb(base + 1); + val = inb(base + 1); + spin_unlock_irqrestore(&cc770_isa_port_lock, flags); + + return val; } static void cc770_isa_port_write_reg_indirect(const struct cc770_priv *priv, int reg, u8 val) { unsigned long base = (unsigned long)priv->reg_base; + unsigned long flags; + spin_lock_irqsave(&cc770_isa_port_lock, flags); outb(reg, base); outb(val, base + 1); + spin_unlock_irqrestore(&cc770_isa_port_lock, flags); } static int __devinit cc770_isa_probe(struct platform_device *pdev) |